Subject: [PATCH v2] perf: Use pre-empt safe cpu_get/put insted of smp_processor_id

From: [email-masked] (Kevin Hilman)
Date: Mon, 10 Sep 2012 09:54:28 -0700

Roger Quadros <[email-masked]> writes:

> gets rid of below messages with CONFIG_DEBUG_PREEMPT enabled
>
> [   28.832916] debug_smp_processor_id: 18 callbacks suppressed
> [   28.832946] BUG: using smp_processor_id() in preemptible [00000000] code: modprobe/1763
> [   28.841491] caller is pwrdm_set_next_pwrst+0x54/0x120
>
> changes in v2:
> - rebased on 3.6-rc5
> - use put_cpu() immediately after get_cpu() in omap3_pm_idle()
>
> Signed-off-by: Roger Quadros <[email-masked]>

Can you also add what platforms this was tested on?

Otherwise, this looks good, and I'll queue up for v3.7 (since it's not a
regression.)

Thanks,

Kevin

> ---
>  arch/arm/mach-omap2/clock.c       |    9 ++++++---
>  arch/arm/mach-omap2/pm34xx.c      |   12 ++++++++----
>  arch/arm/mach-omap2/powerdomain.c |    6 ++++--
>  3 files changed, 18 insertions(+), 9 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/clock.c b/arch/arm/mach-omap2/clock.c
> index ea3f565..06747b6 100644
> --- a/arch/arm/mach-omap2/clock.c
> +++ b/arch/arm/mach-omap2/clock.c
> @@ -285,7 +285,8 @@ void omap2_clk_disable(struct clk *clk)
>  	pr_debug("clock: %s: disabling in hardware\n", clk->name);
>  
>  	if (clk->ops && clk->ops->disable) {
> -		trace_clock_disable(clk->name, 0, smp_processor_id());
> +		trace_clock_disable(clk->name, 0, get_cpu());
> +		put_cpu();
>  		clk->ops->disable(clk);
>  	}
>  
> @@ -339,7 +340,8 @@ int omap2_clk_enable(struct clk *clk)
>  	}
>  
>  	if (clk->ops && clk->ops->enable) {
> -		trace_clock_enable(clk->name, 1, smp_processor_id());
> +		trace_clock_enable(clk->name, 1, get_cpu());
> +		put_cpu();
>  		ret = clk->ops->enable(clk);
>  		if (ret) {
>  			WARN(1, "clock: %s: could not enable: %d\n",
> @@ -380,7 +382,8 @@ int omap2_clk_set_rate(struct clk *clk, unsigned long rate)
>  
>  	/* dpll_ck, core_ck, virt_prcm_set; plus all clksel clocks */
>  	if (clk->set_rate) {
> -		trace_clock_set_rate(clk->name, rate, smp_processor_id());
> +		trace_clock_set_rate(clk->name, rate, get_cpu());
> +		put_cpu();
>  		ret = clk->set_rate(clk, rate);
>  	}
>  
> diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
> index 05bd8f0..5aa0a11 100644
> --- a/arch/arm/mach-omap2/pm34xx.c
> +++ b/arch/arm/mach-omap2/pm34xx.c
> @@ -346,18 +346,22 @@ void omap_sram_idle(void)
>  
>  static void omap3_pm_idle(void)
>  {
> +	unsigned cpu;
> +
>  	local_fiq_disable();
>  
>  	if (omap_irq_pending())
>  		goto out;
>  
> -	trace_power_start(POWER_CSTATE, 1, smp_processor_id());
> -	trace_cpu_idle(1, smp_processor_id());
> +	cpu = get_cpu();
> +	put_cpu();
> +	trace_power_start(POWER_CSTATE, 1, cpu);
> +	trace_cpu_idle(1, cpu);
>  
>  	omap_sram_idle();
>  
> -	trace_power_end(smp_processor_id());
> -	trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
> +	trace_power_end(cpu);
> +	trace_cpu_idle(PWR_EVENT_EXIT, cpu);
>  
>  out:
>  	local_fiq_enable();
> diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c
> index 69b36e1..138bf86 100644
> --- a/arch/arm/mach-omap2/powerdomain.c
> +++ b/arch/arm/mach-omap2/powerdomain.c
> @@ -169,7 +169,8 @@ static int _pwrdm_state_switch(struct powerdomain *pwrdm, int flag)
>  				       ((state & OMAP_POWERSTATE_MASK) << 8) |
>  				       ((prev & OMAP_POWERSTATE_MASK) << 0));
>  			trace_power_domain_target(pwrdm->name, trace_state,
> -						  smp_processor_id());
> +						  get_cpu());
> +			put_cpu();
>  		}
>  		break;
>  	default:
> @@ -491,7 +492,8 @@ int pwrdm_set_next_pwrst(struct powerdomain *pwrdm, u8 pwrst)
>  	if (arch_pwrdm && arch_pwrdm->pwrdm_set_next_pwrst) {
>  		/* Trace the pwrdm desired target state */
>  		trace_power_domain_target(pwrdm->name, pwrst,
> -					  smp_processor_id());
> +					  get_cpu());
> +		put_cpu();
>  		/* Program the pwrdm desired target state */
>  		ret = arch_pwrdm->pwrdm_set_next_pwrst(pwrdm, pwrst);
>  	}